Circuit assemblies with multiple interposer substrates, and methods of fabrication

Abstract

A combined interposer ( 120 ) includes multiple constituent interposers ( 120. i ), each with its own substrate ( 120. i S) and with a circuit layer (e.g. redistribution layer) on top and/or bottom of the substrate. The top circuit layers can be part of a common circuit layer ( 120 R.T) which can interconnect different interposers. Likewise, the bottom circuit layers can be part of a common circuit layer ( 120 R.B). The constituent interposer substrates ( 120. i S) are initially part of a common wafer, and the common top circuit layer is fabricated before separation of the constituent interposer substrates from the wafer. Use of separated substrates reduces stress compared to use of a single large substrate. Other features are also provided.

The invention claimed is: 
     
       1. A circuit assembly comprising:
 a combined interposer comprising a plurality of constituent interposers, each constituent interposer comprising a substrate, the substrates being laterally spaced from each other; 
 wherein the combined interposer comprises a first circuit layer comprising a circuitry and physically contacting a top surface of two or more of the substrates, the circuitry comprising a circuit extending over at least two of said two or more of the substrates; 
 wherein for each of two or more of the constituent interposers, the constituent interposer comprises a first constituent circuit layer which is part of the first circuit layer, the first constituent circuit layer being present on a top surface of the constituent interposer's substrate, the first constituent circuit layer comprising circuitry; 
 wherein the first circuit layer comprises first contact pads on top; 
 wherein the circuit assembly further comprises one or more circuit modules at least one of which comprises an integrated circuit, the one or more circuit modules overlying the first circuit layer, each circuit module comprising one or more contact pads attached to one or more first contact pads; 
 wherein at least a portion of at least one first contact pad overlies a gap separating at least two of the adjacent substrates from each other. 
 
     
     
       2. The circuit assembly of  claim 1  wherein the first circuit layer comprises a circuit connected to first contact pads located over different ones of the substrates. 
     
     
       3. The circuit assembly of  claim 1  wherein the gap separating the substrates from each other has a higher CTE and/or lower elasticity modulus and/or lower stiffness than each of the substrates. 
     
     
       4. The circuit assembly of  claim 1  wherein the substrates are inorganic, and are joined together by a material comprising an organic polymer. 
     
     
       5. A circuit assembly comprising:
 a combined interposer comprising a plurality of constituent interposers, each constituent interposer comprising a substrate, the substrates being laterally spaced from each other; 
 wherein the combined interposer comprises a first circuit layer comprising a circuitry and physically contacting a top surface of two or more of the substrates, the circuitry comprising a circuit extending over at least two of said two or more of the substrates; 
 wherein for each of two or more of the constituent interposers, the constituent interposer comprises a first constituent circuit layer which is part of the first circuit layer, the first constituent circuit layer being present on a top surface of the constituent interposer's substrate, the first constituent circuit layer comprising circuitry; 
 wherein the first circuit layer comprises first contact pads on top; 
 wherein the circuit assembly further comprises one or more circuit modules at least one of which comprises an integrated circuit, the one or more circuit modules overlying the first circuit layer, each circuit module comprising one or more contact pads attached to one or more first contact pads; 
 wherein the combined interposer comprises a second circuit layer comprising circuitry and physically contacting a bottom surface of one or more of the substrates; 
 wherein for each of one or more of the constituent interposers, the constituent interposer comprises a second constituent circuit layer which is part of the second circuit layer, the second constituent circuit layer being present on a bottom surface of the constituent interposer's substrate, the second constituent circuit layer comprising circuitry; 
 wherein the second circuit layer comprises each second constituent circuit layer; 
 wherein the second circuit layer comprises second contact pads on the bottom; 
 wherein one or more of the constituent interposers each comprise one or more conductive through-paths passing through the constituent interposers' substrates, each conductive through-path being connected to at least one first constituent circuit layer and at least one second constituent circuit layer. 
 
     
     
       6. The circuit assembly of  claim 5  wherein at least a portion of at least one second contact pad underlies a gap separating at least two of the adjacent substrates from each other. 
     
     
       7. The circuit assembly of  claim 5  wherein the second circuit layer comprises a circuit extending under different substrates. 
     
     
       8. The circuit assembly of  claim 7  wherein at least one of the first and second circuit layers comprises a circuit connected to conductive through-paths of different constituent interposers. 
     
     
       9. A circuit assembly comprising:
 a combined interposer comprising a plurality of constituent interposers, each constituent interposer comprising a substrate, the substrates being laterally spaced from each other; 
 wherein the combined interposer comprises a first circuit layer comprising a circuitry and physically contacting a top surface of one or more of the substrates; 
 wherein for each of one or more of the constituent interposers, the constituent interposer comprises a first constituent circuit layer which is part of the first circuit layer, the first constituent circuit layer being present on a top surface of the constituent interposer's substrate, the first constituent circuit layer comprising circuitry; 
 wherein the first circuit layer comprises each first constituent circuit layer, and continuously extends from at least one first constituent circuit layer laterally beyond the corresponding substrate; 
 wherein the first circuit layer comprises first contact pads on top; 
 wherein the circuit assembly further comprises a plurality of circuit modules each of which comprises an integrated circuit, the plurality of circuit modules overlying the first circuit layer, each circuit module comprising one or more contact pads attached to one or more first contact pads, the first circuit layer comprising a circuit interconnecting at least two first contact pads attached to contact pads of different ones of said circuit modules; 
 wherein at least one said circuit module comprises a plurality of said contact pads which are attached to first contact pads which are not located over any single one of the substrates. 
 
     
     
       10. The circuit assembly of  claim 9  wherein the substrates are inorganic, and are joined together by a material comprising an organic polymer. 
     
     
       11. A circuit assembly comprising:
 a combined interposer comprising a plurality of constituent interposers, each constituent interposer comprising a substrate, the substrates being laterally spaced from each other; 
 wherein the combined interposer comprises a first circuit layer comprising a circuitry and physically contacting a top surface of one or more of the substrates; 
 wherein for each of one or more of the constituent interposers, the constituent interposer comprises a first constituent circuit layer which is part of the first circuit layer, the first constituent circuit layer being present on a top surface of the constituent interposer's substrate, the first constituent circuit layer comprising circuitry; 
 wherein the first circuit layer comprises each first constituent circuit layer, and continuously extends from at least one first constituent circuit layer laterally beyond the corresponding substrate; 
 wherein the first circuit layer comprises first contact pads on top; 
 wherein the circuit assembly further comprises one or more circuit modules at least one of which comprises an integrated circuit, the one or more circuit modules overlying the first circuit layer, each circuit module comprising one or more contact pads attached to one or more first contact pads; 
 wherein the combined interposer comprises a second circuit layer comprising circuitry and physically contacting a bottom surface of one or more of the substrates; 
 wherein for each of one or more of the constituent interposers, the constituent interposer comprises a second constituent circuit layer which is part of the second circuit layer, the second constituent circuit layer being present on a bottom surface of the constituent interposer's substrate, the second constituent circuit layer comprising circuitry; 
 wherein the second circuit layer comprises each second constituent circuit layer; 
 wherein the second circuit layer comprises second contact pads on the bottom; 
 wherein one or more of the constituent interposers each comprise one or more conductive through-paths passing through the constituent interposers' substrates, each conductive through-path being connected to at least one first constituent circuit layer and at least one second constituent circuit layer. 
 
     
     
       12. The circuit assembly of  claim 11  further comprising a circuit element passing between at least two of the substrates, for connecting a contact pad or other circuit element above the substrates to a contact pad or other circuit element below the substrates. 
     
     
       13. A circuit assembly comprising a combined interposer comprising:
 a plurality of inorganic substrates, the inorganic substrates laterally spaced from each other and being separated from each other by a gap pattern comprising organic polymeric material joining together the inorganic substrates; 
 a plurality of first contact pads at a top of the combined interposer and a plurality of second contact pads at a bottom of the combined interposer, the first and second contact pads being attachable to circuit elements outside of the combined interposer; 
 one or more circuits each of which interconnects one or more first contact pads and one or more second contact pads, at least one said circuit passing through the organic polymeric material in the gap pattern between a region above the inorganic substrates and a region below the inorganic substrates. 
 
     
     
       14. The circuit assembly of  claim 13  wherein at least one said circuit passes through one of said inorganic substrates. 
     
     
       15. A circuit assembly comprising:
 a combined interposer comprising a plurality of constituent interposers, each constituent interposer comprising a substrate, the substrates being laterally spaced from each other; 
 wherein the combined interposer comprises a first circuit layer comprising a circuitry and physically contacting a top surface of two or more of the substrates, the circuitry comprising a circuit extending over at least two of said two or more of the substrates; 
 wherein for each of two or more of the constituent interposers, the constituent interposer comprises a first constituent circuit layer which is part of the first circuit layer, the first constituent circuit layer being present on a top surface of the constituent interposer's substrate, the first constituent circuit layer comprising circuitry; 
 wherein the first circuit layer comprises first contact pads on top; 
 wherein the combined interposer further comprises second contact pads on the bottom, and comprises one or more circuits each of which passes through a gap between adjacent ones of the substrates from a region above the substrates to a region below the substrates and is connected to one or more first contact pads and to one or more second contact pads. 
 
     
     
       16. The circuit assembly of  claim 15  wherein the substrates are inorganic, and are joined together by a material comprising an organic polymer.